W2 valve size recommendations

on those heads I'd
use smaller than 1.6 exhaust except you say VJ is already roughed in
do the conversion guides easy choice is 11/32 but perhaps you can score some 5/16 or MM valves
but use something popular like SBC or LS
I would first talk with B3
I'd port first for a 2.2 or not too much bigger valve and get that working right- depending on bore size
then go bigger next time
It's hard to put metal back
or find someone with lots of experience with W2
we had several here in SO Cal but have not heard of any flow bench work in like forever
try and get the flow as high as possible at each lift or as eariy as possible

I have a head (somewere is its mate) that am going to check out putting the hold down with something like a double end stud
put the shaft behind the stud (instead of elongating the hold down hole notch the intake side of the shaft)
perhaps another hold down on the intake rail side
then fit some high ratio long arm- essentially backset trunion rockers
pushrod as to stay in about the same place coming through the head
this solves the problem of the adjuster getting too close to the rocker body
although I think you might get 1.7 with cup type adjusters but most I've seen is 1.65
problem is small for today base circle
those that can run large cam bore have it easier
Did you see krooser's pic of chevy and mopar cam (or BBC) big difference
And I can remember makeing SBC even smaller made spark jump like cam was spaghetti
AMC ,LS & Ford have it easier